Does any solution exist for RTC with following consideration?
- Does not have to be battery backed. The time can be set using a network clock at the OS (Linux) startup.
- The time needs to be accessible at high memory access speeds (I2C may be slow). Possibly mmap'd to user space for reading the time at least.
- Provides millisecond granularity.
- Does ARM processor itself provide any such capability? Perhaps a count down register that can be used to emulate real time keeping?